The Stable channel has been updated to 39.0.2171.85 (Platform version: 6310.48.0) for all Chrome OS devices except Dell Chromebook 11, HP Chromebook 14, Acer C720 and the Toshiba Chromebook. This build contains a number of bug fixes, security updates and feature enhancements. Systems will be receiving updates over the next couple weeks as the team takes a break over the holiday. Here is a list of Chromium changes.

Some highlights of these changes are:

Enable Chromecast support for media files stored on Google Drive

Update Network Error page design

Display apps installed in Google Drive in the Chrome OS Launcher

If you find new issues, please let us know by visiting our forum or filing a bug. Interested in switching channels? Find out how. You can submit feedback using ‘Report an issue...’ in the Chrome menu (3 horizontal bars in the upper right corner of the browser).

looks like display scale factor was removed in chrome flags, which is making the UI on the toshiba chromebook 2 small again. i can zoom the web page in settings, but the rest of the UI is tiny and the fonts looks blurry too for some reason. scale factor worked really well for hidpi screens in 38, wonder why it was removed?

I noticed BUILD DATE has no date showing when you click on 'about chrome os' and click 'more info'. Also, my profile photo reverted back to an old one. I had to manually click 'people' in 'settings' then click my photo. It then automatically updated to my current photo. Just an FYI.

If your device is one which did not yet get the update, I wouldn't be concerned. According to OMG CHROME, these devices will eventually get the same update over the coming weeks. Read under 'Getting the Update'. Source: http://www.omgchrome.com/latest-chrome-os-stable-release-adds-drive-apps-chromecast-features/